建 议 改 成:自 闭 矩 阵 题目 题目描述: 计算一个满足下列条件的,n x n的矩阵的数量(答案对mod取余) * Ai, j ∈ {0, 1, 2} for all 1 ≤ i, j ≤ n. * Ai, j = Aj, i for all 1 ≤ i, j ≤ n. * Ai, 1 + Ai, 2 + ... + Ai, n = 2 for all 1 ≤ i ≤ n. * A1, 1 = A2, 2 = ... = An, n = 0. 输入描述: 多组输入,每行输入两个整数,n和mod * 1 ≤ n ≤ 105 * 1...